In the perception of music one does not need acoustical energy at the fundamental frequency of periodic sounds in order to perceive a musical pitch. Sounds which are merely arbitrary pairs of successive harmonics of low order, presented either monotically or dichotically, evoke pitch sensations corresponding to the missing fundamental frequencies. These pitch sensations become more ambiguous with increasing harmonic numbers, as evidenced by confusions subjects make when asked to identify muscial intervals played with such sounds. A black box model has recently been developed describing the processing from stimulus frequencies to muscial pitch in very general mathematical terms. It explains a host of data existing in the literature on pitch perception. We propose to subject this powerful theory to a rigorous test by a series of psychophysical pitch confusion experiments which will examine the the theory's predictions of pitch ambiguities. By this procedure we expect to gain understanding of the tone stimulus - to - pitch sensation process in a general sense, without speculating on a particular mechanism or physiological details. We expect that this approach, because of its generality, may prove to be relevant to other sense modalities as well, and may provide insight into a variety of possible hearing defects which are now commonly referred to as "tone deafness".